/* ===== Theme ===== */
:root{
  --accent:#a50034; /* Cornell-like red */
  --ink:#161616;
  --muted:#666;
  --bg:#fff;
  --card:#f8f8f8;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{font-family:system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,'Helvetica Neue',Arial,sans-serif;color:var(--ink);background:var(--bg);line-height:1.65}
img{max-width:100%;height:auto;display:block}
.container{max-width:1100px;margin-inline:auto;padding:1.25rem}

/* ===== Header & Nav ===== */
.site-header{background:var(--accent);color:#fff;position:sticky;top:0;z-index:10}
.header-grid{display:flex;align-items:center;justify-content:space-between;gap:1rem}
.brand{margin:0;font-size:1.6rem}
.tag{margin:.25rem 0 0;opacity:.9}
.nav a{color:#fff;text-decoration:none;margin-left:1rem;font-weight:600}
.nav a:hover{opacity:.8}

/* ===== Sections ===== */
.section{padding:2.5rem 0}
.section.alt{background:var(--card)}
h2{color:var(--accent);margin:0 0 1rem;font-size:1.6rem}
.muted{color:var(--muted)}
.subtle{color:var(--muted);font-size:.95rem}

/* ===== About ===== */
.about-grid{display:grid;grid-template-columns:320px 1fr;gap:2rem;align-items:center}
.about-image img{border-radius:50%;box-shadow:0 8px 24px rgba(0,0,0,.15)}
.cta-row{margin-top:1rem;display:flex;gap:.75rem;flex-wrap:wrap}
.btn{display:inline-block;padding:.6rem 1rem;border-radius:.6rem;background:var(--accent);color:#fff;text-decoration:none;font-weight:700}
.btn:hover{opacity:.92}
.btn.outline{background:transparent;border:2px solid var(--accent);color:var(--accent)}

/* ===== Cards / Highlights ===== */
.cards{display:grid;grid-template-columns:1fr;gap:1rem}
.cards.three{grid-template-columns:repeat(3,1fr)}
.card{background:#fff;border-radius:1rem;padding:1rem;box-shadow:0 4px 18px rgba(0,0,0,.06)}
.card h3{margin:.25rem 0 .5rem}

/* ===== Timeline ===== */
.timeline{list-style:none;padding:0;margin:0}
.timeline li{padding:1rem;background:#fff;border-radius:1rem;box-shadow:0 4px 18px rgba(0,0,0,.06);margin-bottom:1rem}

/* ===== Skills ===== */
.two-col{display:grid;grid-template-columns:1fr 1fr;gap:2rem;align-items:start}
.pill-list{list-style:none;padding:0;margin:.5rem 0 1rem;display:flex;gap:.5rem;flex-wrap:wrap}
.pill-list li{padding:.35rem .7rem;border-radius:999px;background:var(--card);border:1px solid #eee}

/* ===== Publications & Talks ===== */
.pub-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.pub-list li {
  padding: 0.75rem 0 0.75rem 0.75rem; /* space for border on hover */
  margin-bottom: 0.75rem;
  border-bottom: 1px solid #ddd;
  line-height: 1.6;
  transition: background 0.2s ease, border-left 0.2s ease;
  border-radius: 0.25rem;
}

.pub-list li:last-child {
  border-bottom: none;
}

.pub-list li:hover {
  background: #f9f9f9;                  /* soft gray highlight */
  border-left: 4px solid var(--accent); /* Cornell red accent */
}

.pub-list em {
  display: block;
  font-style: italic;
  font-weight: 500;
  color: #111;
  margin-bottom: 0.25rem;
}

.text-link {
  color: var(--accent);
  font-weight: 600;
  text-decoration: none;
}
.text-link:hover {
  text-decoration: underline;
}
/* ===== Contact ===== */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:2rem;align-items:center}
.contact-list{list-style:none;padding:0;margin:0}
.contact-list li{padding:.25rem 0}
.contact a{color:var(--accent);text-decoration:none}
.contact a:hover{text-decoration:underline}

/* ===== Footer ===== */
.site-footer{border-top:1px solid #eee}
.footer-grid{display:flex;align-items:center;justify-content:space-between;gap:1rem}
.tiny{color:var(--muted);font-size:.9rem}

/* ===== Responsive ===== */
@media (max-width: 980px){
  .cards.three{grid-template-columns:1fr 1fr}
  .two-col{grid-template-columns:1fr}
  .about-grid{grid-template-columns:1fr}
  .contact-grid{grid-template-columns:1fr}
  .nav{display:none} /* simplifies header on mobile */
}
@media (max-width: 640px){
  .cards.three{grid-template-columns:1fr}
}
#leadership .card img {
  display: block;
  margin: 0 auto 1rem auto; /* centers + gives bottom spacing */
  border-radius: 0.75rem;
}
.cards.two {
  display: grid;
  grid-template-columns: 1fr 1fr; /* 2 equal columns */
  gap: 1.5rem;
}

.photo-stack {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.photo-stack img {
  width: 100%;
  border-radius: 0.75rem;
  box-shadow: 0 4px 12px rgba(0,0,0,.08);
  object-fit: cover;
  aspect-ratio: 16 / 10; /* keeps them same height */
}

@media (max-width: 768px) {
  .cards.two { grid-template-columns: 1fr; } /* stack on mobile */
}